Probability of Ignition From Fine Fuel Calculator
Summarize already observed independently matched fine-fuel ignition outcomes and unknown assessments, not fire experimentation instructions or a validated ignition probability forecast. Caller independently verifies units, applicability and matching conditions; no operational recipe, safety certification, causal efficacy or legal/resource classification is inferred.
Description
Observed ignition frequency summarizes independently recorded cases under a specified sampling design.
Observed ignition frequency summarizes independently recorded cases under a specified sampling design.1
Known-case weighting and missing coverage must be distinguished from a calibrated future ignition probability. Use this tool to calculate probability of ignition from fine fuel from the supplied measurements and assumptions.
When to use Probability of Ignition From Fine Fuel Calculator
Use this tool to calculate probability of ignition from fine fuel from the supplied measurements and assumptions. Establish the species/site, survey protocol, units, sampled area or exposure, and the independently chosen reference or model.
How to use Probability of Ignition From Fine Fuel Calculator and understand its results
- Establish the species/site, survey protocol, units, sampled area or exposure, and the independently chosen reference or model.
- Enter observedFineFuelTrialWeights, observedIgnitionFlags, knownIgnitionAssessmentFlags, using the field meanings and rules below, then run the tool.
- Read knownWeightedIgnitionFraction, unassessedTrialWeightFraction. Interpret the fields using their units, signs and evidence conventions below.
- If input validation fails, correct the reported field and run again. Before applying the result, check reference scope, model assumptions and any missing evidence or placeholder values.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| observedFineFuelTrialWeights | Observed fine fuel trial weights | list of number | Required |
| observedIgnitionFlags | Observed ignition flags; binary 0/1 under the definitions below | list of number | Required |
| knownIgnitionAssessmentFlags | Known ignition assessment flags; binary 1=known, 0=unknown, in the order described below | list of number | Required |
Enter nonempty aligned nonnegative exposure weights and binary ignition and known flags. Require positive total weight and positive known weight. Divide known positive weight by known weight and separately return unknownWeight/totalWeight. Output is an observed weighted fraction without percent scaling or predictive calibration.
knownIgnitionFraction=Σweight×ignition×known/Σweight×known; unknownWeightFraction=Σweight×(1−known)/Σweight Use the exact units, boundary rules, ordering and missing-evidence conventions above.
| Output field | Meaning | Value type |
|---|---|---|
| knownWeightedIgnitionFraction | Known Weighted Ignition Fraction; follow the units, sign, ordering and evidence convention stated above | number |
| unassessedTrialWeightFraction | Unassessed Trial Weight Fraction; follow the units, sign, ordering and evidence convention stated above | number |
{
"input": {
"observedFineFuelTrialWeights": [
1,
2,
1
],
"observedIgnitionFlags": [
1,
0,
1
],
"knownIgnitionAssessmentFlags": [
1,
1,
0
]
},
"output": {
"knownWeightedIgnitionFraction": 0.3333333333333333,
"unassessedTrialWeightFraction": 0.25
}
}Limitations and assumptions
Known-case weighting and missing coverage must be distinguished from a calibrated future ignition probability. Interpretation depends on the units, sampling scope and exact model described above.
All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse evidence arrays fail validation; the specific bounds and alignment requirements are stated above. Extremely large inputs or outputs can also be rejected. An input error is distinct from a successful result reporting false, no matches or missing evidence.
Alternative or Complementary methods
Use Rothermel Surface Rate of Spread Calculator for this related task: A Rothermel-style spread relation balances reaction intensity and propagation factors against the energy needed to heat fuel.
Use 100-Hour Moisture Class Lookup when its separate inputs and assumptions fit the question: A hundred-hour fuel-moisture reference uses a particular fuel class and observation convention.
References
Similar or alternative tools
- Rothermel Surface Rate of Spread Calculator
A Rothermel-style spread relation balances reaction intensity and propagation factors against the energy needed to heat fuel.
- 100-Hour Moisture Class Lookup
A hundred-hour fuel-moisture reference uses a particular fuel class and observation convention.